Method and system for replacing an air filter

ABSTRACT

An air intake of an air handling or HVAC system, such as located in a ceiling of a structure, includes a movable filter housing. The filter housing comprises a grate configured to support one or more air filters at a top side thereof. The filter housing is mounted via one or more extendable connectors and includes a control tool mount. Connection of a control tool to the filter housing allows a user to pull the filter housing downwardly to a lowered position for replacing the air filter(s). The filter housing may be biased upwardly to its use position and may include a latch or lock to secure it in the use position.

RELATED APPLICATION DATA

This application is a continuation-in-part of U.S. application Ser. No.14/846,257, filed Sep. 4, 2015, which is a continuation-in-part of U.S.application Ser. No. 14/487,929, filed Sep. 16, 2014, now U.S. Pat. No.9,127,856, issued Sep. 8, 2015, which claims priority to U.S.Provisional Patent Application Ser. No. 61/887,533, filed Oct. 7, 2013and to U.S. Provisional Patent Application Ser. No. 61/907,027, filedNov. 21, 2013. The present application claims priority to andincorporates by reference in their entirety each of said priorapplications.

FIELD OF THE INVENTION

The present invention relates to air filters for ventilation systemsand, more particularly, the replacement of such filters.

BACKGROUND OF THE INVENTION

Building air ventilation systems typically include one or more airfilters. These filters are generally positioned to filter air which isdrawn from the interior of the building through an air handling system(which may heat and/or cool the air) before the air is discharged backinto the building.

For example, in the case of a home, a standard air heating and coolingsystem typically includes one or more air intakes which are located inthe interior of the home. An air filter is often located at each intakefor filtering the air as it is drawn into the system. These air filtersmust be regularly changed so that they are effective in removingparticulates from the air and so that the filter does not become cloggedand impair the air flow through the system.

Unfortunately, the replacement of a used air filter with a new one isoften very difficult. For example, home air heating and cooling systemsfrequently utilize air intakes which are located in the ceiling. Theintake includes a housing or plenum which leads to the air handlingdevices (fans, heating and/or cooling coils, etc.). An air filter ismounted at the entrance to the intake, such as between a flange thereofand a covering grill or grate. The grate is typically pivotally mountedto the intake housing, such as with hinges. The grate can be maintainedin its closed position by one or more latches.

Various difficulties arise when replacing the air filter of such amechanism. First, the user must generally stand on a ladder in order toreach and unlatch the covering grate due to the in-ceiling location ofthe intake. This requires a user to balance himself on the ladder whileattempting to unlatch the latches, which may involve the use of one ormore tools.

In addition, once the grate is unlatched, it must swing down from theceiling to its open position. Because the user must generally positionhimself under the grate in order to unlatch it, this swinging motion mayeither result in the grate hitting the user or the user being forced tochange positions on the ladder to allow the grate to swing by them.Either of these actions may result in the user falling from the ladder.

Once the grate is open, the filter is unsecured and will then fall fromthe intake under the force of gravity. This may cause a dirty filter tohit the user, the ladder, the floor or other items, causing the airfilter to shed dust and make a significant mess. As a result, the usermust generally stay on the ladder and, while avoiding the swinginggrate, grasp the used filter.

The user then must climb down the ladder and obtain a new filter. Theuser then reverses the process, placing the new filter into the intakeand attempting to swing the grate back into place and latch it to holdthe new filter.

Some attempts have been made to address these issues, but they alsosuffer from various problems. For example, U.S. Pat. No. 8,075,031describes a filter changing system where a user attempts to use a polewith filter grabbing teeth in order to remove a used filter. Thismechanism, however, does not address the significant problem with theinterplay between the grate and the filter. The system of the '031patent requires that the user turn on their air system while opening thegrate or else the used filter will fall. First, a user may not rememberto turn on their air system when replacing the system. Second, in somecases this arrangement may not work. For example, some ceiling ventsutilize two side-by-side filters. Once a user removes one of thesefilters there will be insufficient suction to maintain the other filterin place and it will fall on the user. In addition, this system requiresthat the user attempt to align a large filter element which as closetolerances to the intake housing, remotely via a pole in order to get anew filter placed into the intake housing.

In addition, some commercial ventilation systems have filter housingwhich are movable. These systems are generally very large and complexand typically utilize motors or other automated controls to move thehousings.

SUMMARY OF THE INVENTION

Aspects of the invention comprise, among other things, air intakes withmovable filter housings, kits for retrofitting air intakes to includemovable filter housings, and methods of removing and replacing airfilters. Embodiments of the invention have particular applicability toair intakes which are located in the ceiling of a structure. In such aconfiguration, a filter housing which is configured to accept one ormore air filters is movably mounted relative to the air intake.Preferably, the filter housing is mounted for vertical movement betweena raised or closed position in which the one or more filters are locatedat the air intake to filter air flowing into the air intake, and alowered position in which the one or more filters are readily accessiblefor removal and replacement.

One embodiment of the invention comprise a raisable and lowerable filterhousing for an air heating/cooling system having an air intake locatedin a ceiling, the air intake comprising an air return having an airinlet. The filter housing preferably comprises an air intake support,such as a grate having an outer side and an inner side and at least onefilter mount for receiving at least one air filter at the inner side ofthe grate; at least one extendable connector having at least a firstportion and a second portion, the first portion connected to the airfilter housing; and at least one control tool mount configured toconnect a control tool. When the second portion of the at least oneextendable connector is connected to the support structure, the airfilter housing is movable between a raised position in which the grateis positioned at the air inlet of the air intake return and the at leastone air filter associated with the air filter housing is configured tofilter air passing through the air intake grate into the air intakereturn of the air heating/cooling system, and such that when a controltool is connected thereto, a user may lower the air filter housing to alowered position in which the air filter housing is positioned adistance vertically below the air intake, permitting a user to removeand replace the at least one air filter.

In one embodiment, multiple filter mounts are located at an inner sideof the air intake support or grate. The filter mounts may define aplurality of vertically stacked air filter slots, whereby two or moreair filters may be arranged in a stacked arrangement at the inner sideof the air intake support or grate.

The one or more extendable connectors may comprise cables. The cablesmay be biased into a retracted position for biasing the filter housingto its retracted position. The biasing mechanisms may be independentlyadjusted by the user.

In one embodiment, the filter housing further comprises at least onelatch for selectively locking or retaining the filter housing in itsretracted position.

The control tool may comprise an elongate pole. The control tool mountmay comprise a threaded opening accessible at the outer or bottom sideof the grate, such as for accepting a threaded end of the pole. The poleor other control tool may be weighted, such as by attachment to a dolly,so that the control tool maintains the filter housing in its extendedposition against an upward biasing force applied by the one or moreconnectors. In another embodiment, one or more brakes may be used toselectively maintain the position of the air filter housing, such as tomaintain the air filter housing in its lowered position. The one or morebrakes may, for example, engage biased pulleys which reel the extendableconnectors. The one or more brakes are preferably user controllable,such as via the pole or other control tool.

One embodiment of the invention is an air filter condition indicator.The air filter condition indicator may be associated with the air filterhousing of the invention to provide an indication of the air filtersassociated therewith. The air filter indicator may comprise one or morean air flow passages in communication with an exterior side of the airfilter housing and an interior side thereof, at least one air sensorassociated with the at least one passage, and at least one conditionindicator. The air sensor(s) may sensor or measure the air pressure orspeed through or in the one or more passages. A condition of theindicator may be based upon the output of the at least one air sensor.The indicator may comprise one or more visual or audible indicators,such as one or more lights. In one embodiment, the indicator maycomprise a green light when the one or more air sensors sense a lowpressure in the passage and a red light when a high pressure isdetected.

Further objects, features, and advantages of the present invention overthe prior art will become apparent from the detailed description of thedrawings which follows, when considered with the attached figures.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an air intake of the present invention as located ina ceiling of a structure, the air intake comprising a filter housing;

FIG. 2 is a cross-sectional view of the air intake which is illustratedin FIG. 1, along with an access tool of the invention;

FIG. 3 illustrates a filter housing of the present invention with an airfilter removed there from;

FIG. 4 illustrates a filter housing latching system of the presentinvention;

FIG. 5 illustrates a filter housing and associated control tool of theinvention;

FIG. 6 is a cross-sectional view of an air intake of the presentinvention with an access tool connected to a filter housing thereofwhile the filter housing is in a retracted position;

FIG. 7 is cross-sectional view of the air intake of FIG. 6 with thefilter housing moved to a lowered, air filter access position;

FIG. 8A is a cross-sectional view of a filter housing kit forinstallation relative to an air intake;

FIG. 8B is a cross-sectional view of a filter housing installationconfiguration according to an embodiment of the invention;

FIGS. 9 and 10 illustrate a braking mechanism in accordance with anembodiment of the invention;

FIG. 11 illustrates a filter housing having a stacked filterconfiguration in accordance with the present invention;

FIG. 12 illustrates, in partial cross-section, an embodiment of a grateor grill of a filter housing in accordance with the present invention;

FIG. 13 illustrates a filter housing having a filter change indicator inaccordance with the present invention; and

FIG. 14 illustrates detailed of a filter change indicator in accordancewith an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following description, numerous specific details are set forth inorder to provide a more thorough description of the present invention.It will be apparent, however, to one skilled in the art, that thepresent invention may be practiced without these specific details. Inother instances, well-known features have not been described in detailso as not to obscure the invention.

Embodiments of the invention comprise air intakes with movable filterhousings, kits for retrofitting air intakes to include movable filterhousings, and methods of removing and replacing air filters. Embodimentsof the invention have particular applicability to air intakes which arelocated in the ceiling of a structure. In such a configuration, a filterhousing which is configured to accept one or more air filters is movablymounted relative to the air intake. Preferably, the filter housing ismounted for vertical movement between a raised or closed position inwhich the one or more filters are located at the air intake to filterair flowing into the air intake, and a lowered position in which the oneor more filters are readily accessible for removal and replacement.

FIG. 1 illustrates an air intake 20 for an air system, such as an airheating and/or cooling system (often referred to as an HVAC system). Theair intake 20 is located at a ceiling C of a structure such as a house.

As illustrated in FIG. 2, the air intake 20 comprises an air intakereturn 22. The air return 22 may have various configurations, dependingupon the particular installation. FIG. 2 illustrates one configurationwhere the air return 22 generally comprises a box-shaped structure 24.One end of the air return 22 defines an air inlet 26 and the otherpreferably defines an exit path or opening, such as defined by a duct28, through which air flows to an air handling device such as a fan. Theair return 22 is preferably supported in the ceiling C, such as by oneor more supports 30, such as 2 inch by 4 inch wooden or metal studs. Theair inlet 26 is aligned with an opening which is defined in the ceilingC, whereby air may flow from an interior space of the structure throughthe opening in the ceiling C and into the air return 22 to the airhandling system (such as for heating or cooling the air and thenreturning the air back into the structure at one or more vents, as iswell known).

The shape of the air inlet 26 may vary and may be square, rectangular orother shapes. The dimensions of the air inlet 26 may also vary, but arecommonly set sizes, such as 20 inches by 20 inches, 20 inches by 30inches or the like.

Referring FIGS. 1-3, in accordance with the invention, a filter housing40 is selectively locatable at the air inlet 26 of the air return 22.The filter housing 40 preferably comprises a grill or grate, or othersupport. The grate may be constructed from metal, or to reduce weight,be constructed from plastic or other materials. The filter housing 40has a top or inside 42 and bottom or outside 44. One or more openings 54are defined through the filter housing 40 from the bottom 44 to the top42, thus permitting air to flow through the filter housing 40. In oneembodiment, the openings 54 are located in a central portion of thefilter housing 40 and a generally closed flange extends 56 around theperiphery.

Referring to FIG. 12, in one embodiment, the grill or grate portion ofthe filter housing 40 comprises a plurality of spaced supports 55. Theair flow openings 54 are defined between the supports 55 (and/or betweenthe supports 55 and the frame of the grill or grate). In one embodimentof the invention, the supports 55 have a “U” shaped, circular or otherarcuate cross-section facing at least the bottom 44. In this manner, theair flow around the supports 55 and through the openings 54 is much lessturbulent. This makes reduces the noise associated with the air beingdrawn through the filter housing 40, whereby the filter housing 40operates more quietly than conventional air filter grates which usegenerally flat metal slats.

The filter housing 40 may have various shapes, but preferably has aperipheral shape which matches the shape of the air inlet 26 and ispreferably closely sized to the air inlet 26 so that the majority of airwhich is drawn into the air inlet 26 must pass through the filterhousing 40.

In a preferred embodiment of the invention, the filter housing 40 isconfigured to support at least one air filter 46. In a preferredembodiment, as illustrated in FIG. 3, the air filter 46 is configured tobe removably supported at the top 42 of the filter housing 40. In oneembodiment, a filter mount 48 is defined by or attached to the filterhousing 40 and is located at the top 42 of the filter housing 40. Asillustrated, the filter mount 48 may comprise at least a first support50 a and an opposing second support 50 b. The supports 50 a,b are spacedfrom one another, with each support 50 a,b preferably mounted to theflange 56 of the filter housing 40 (outside of the openings 54), andextend upwardly from the filter housing 40. In one embodiment, eachsupport 50 a,b has an inwardly extending flange 52. The inwardlyextending flanges 52 are spaced from the filter housing 40, preferablyby a distance which is slightly greater than the thickness of an airfilter 46. As described in more detail below, in such a configuration,an air filter 46 can be removably inserted into the filter mount 48 in ahorizontal direction, as illustrated in FIG. 3. In a preferredembodiment, the at least one air filter is supported above the grate orgrill (e.g. the bottom of the filter does not sit or rest upon the topsof the supports of the grate or grill, but is spaced or set upwardlytherefrom).

The filter housing 40 may have other configurations. For example,instead of defining or including a grate, the filter housing 40 mightmerely comprise a peripheral frame around one or more large openings.The one or more air filters 46 may then be supported so that they extendover the one or more openings (instead of being positioned behind/abovea grate, the one or more filters might span or extend over one or morelarger openings, whereby the weight of the filter housing 40 may bereduced by eliminating much of the central grate).

Preferably, the filter housing 40 is movable relative to the air return22. Most preferably, the filter housing 40 can be moved from a first,raised position in which it is located at the air inlet 26 (asillustrated in FIGS. 2 and 6), to a second, lowered position in which itis positioned below the air inlet 26 (as illustrated in FIG. 7).Preferably, means are provided for movably supporting the filter housing40. Most preferably, this means for movably supporting comprises one ormore mechanical supports.

In one embodiment, the means for movably supporting comprise at leastone, preferably two or more, and most preferably four, extendableconnectors 58. In one embodiment, the connectors 58 comprise cables 60or other flexible members (such as wires, straps or the like). Thecables 60 may comprise solid or braided wire or other durable material.In one embodiment, each cable 60 has a first end which is connected tothe filter housing 40 and a second end which is connected to a mount 62.Each mount 62 may comprise a housing 64, at least one pulley 66 (towhich the second end of the cable is connected), and at least onebiasing element or mechanism (not shown) such as a spring or the likewhich is configured to bias the pulley 66, preferably in a windingdirection as described below. Each mount 62 is preferably connected tothe air return 24.

In a preferred embodiment, there are four cables 60. The first ends ofthe cables 60 are mounted directly or indirectly to the flange 56 of thefilter housing 40 or the supports 50 a,b, so that they are spaced apartfrom one another, contributing to the stability of the unit when it israised and lowered, and so that they are not in the air flow paththrough the filter housing 40 and air intake 26, as described below.

The second end of each cable 60 is configured to be biased by itsrespective pulley 66 or other movable mount. In one embodiment, eachcable 60 winds on or unwinds from its associated pulley 66. In apreferred embodiment, the means for biasing, such the spring, biases itsassociated cable 60 into a wound or retracted position, as described inmore detail below. In one embodiment, a spring tension adjustment oradjuster may be provided. The spring tension adjuster may allow the userto selective adjust the spring tension, thus adjusting the biasing forcewhich is generated by the spring (and thus the upward force on the cable60). For example, relative to a coil spring such as detailed herein, thecoil spring might be mounted on a pin or axle. A user may engage a headof the pin and rotate it (such as with a tool—e.g. a socket wrench,etc.), thus either causing the coil spring to coil more tightly or toloosen it. In one embodiment, a user may adjust the spring tension ofeach spring, and thus control the biasing force applied to each cable60, separately. This allows, for example, a user to customize thebiasing force based upon the particular application of the filterhousing 40. For example, if the filter housing 40 is installed in aceiling which is 20 feet high, a higher spring tension may be needed toraise the filter housing 40 (and the associated cabling) than if thefilter housing is installed in a ceiling which is only 8 feet high.Also, one user might associate 3 or 4 stacked filters with their filterhousing 40 while another use might only use one filter. The first usermight thus need to increase the biasing force to compensate for theextra filter weight. Also, the ability for the user to separatelycontrol or adjust the biasing force allows the user to ensure that thefilter housing 40 is raised upwardly in a level position and not askew(for example, if each cable has 20 ft-lbs of upward bias force but onecorner of the filter housing 40 weighs slightly more than the othercorners/areas, then the filter housing 40 will tilt when it is raisedupwardly; by adjusting the bias applied to the heavier corner, the usercan ensure that the filter housing stays level as it is raised).

In a preferred embodiment, the filter housing 40 further comprises ameans for selectively locking the filter housing 40 to the air return 22or the associated support structure. Referring to FIG. 4, the means forselectively locking may comprise a latch 70. In one embodiment, thelatch 70 comprises a pivot 72 which is rotatably mounted to the filterhousing 40, and one or more arms which are mounted to the pivot 72 andwhich move with the pivot. In one embodiment, the pivot 72 has a firstleg 74 and a second leg 76 which are offset from one another on eitherside of a pivot point P, and which extend in opposing directions fromone another. A first arm 78 extends from the first leg 74 and a secondarm 80 extends from the second leg 82. Each arm 78,80 have a free endwhich is configured to selectively engage an aperture 82 or other matingstructure.

In one embodiment, the apertures 82 are defined in or by the intakereturn 24 or the associated mounting structure there for. When the twoarms 78,80 have the configuration illustrated in FIG. 4, two apertures82 are located in generally opposing positions across from one another.

In one embodiment, the latch 70 is biased to a locked position. Asillustrated in FIG. 4, one or more springs 75 may be utilized for thispurpose. For example, springs 75 may extend between the first leg 74 andthe second leg 76 of the pivot 72 and the filter housing 40 (or, asillustrated, one or more mounts 77 associated with the filter housing40) in a direction which biases the pivot 72 to its latched position. Ofcourse, other mechanisms might be utilized, such as a single spring ormore than two springs, one or more springs (such as coil springs)mounted around and configured to bias a mounting shaft of the pivot 72,etc.

In a preferred embodiment, the latch 70 is configured to be remotelyactuated by a user using a tool. Referring to FIG. 5, in one embodiment,the pivot 72 has a tool connector 100. In one embodiment, the toolconnector 100 comprises a threaded opening or socket which is associatedwith the pivot 72. The connector 100 is configured to accept a firstthreaded portion 84B of an actuating tool.

Preferably, the latch 70 is configured so that when the user turns orthreads the first threaded portion 84B of the tool into engagement withthe mount 100, it causes the pivot 72 to rotate to its unlatchedposition. When the user removes the tool, the latch 70 is biased back toits closed or locked position. As described below, in a preferredembodiment, the tool for unlocking the latch 70 is a pole 86 which isalso used to control the filter housing 40.

In a preferred embodiment, a tool opening O is located centrally to thefilter housing 40, as illustrated in FIGS. 1 and 5. In order to keep thelatch 70 out of the air flow path through the filter housing 40, thepivot 72 and the arms 78,80 may be located behind a structural support,such as a bar 92, of the grate portion of the filter housing 40 (i.e.the arms 78,80 extend in either direction from the pivot 72, parallel tothe bar 92).

In one embodiment, the filter housing 40 includes at least one toolaccepting mount 102. The at least one tool accepting mount 102 isconfigured to accept or connect a control tool for use by a user inmoving the filter housing 40 from its first or retracted position to itssecond or lowered position. In one embodiment, the control toolcomprises an elongate pole 86.

In one embodiment, the pole 86 has at least two portions (though it mayhave more than two portions), such as a bottom portion 90 and a topportion 88. The top portion 88 may be movable relative to the bottomportion 90, such as in a telescopic arrangement which permits the topportion 88 to be extended or retracted relative to the bottom portion90. In one embodiment, means may be provided for selectively locking thetop portion 88 to the bottom portion 90, such as to fix the top portion88 in a particular position.

In one embodiment, the tool accepting connector or mount 102 comprisesthe opening O. This opening O or mount 102 preferably has a firstshoulder portion 104 for accepting a body 84C of the pole 86, and asecond threaded portion 106 for accepting a second threaded portion 84Aof the pole 86. The shoulder portion 104 preferably has a size whichpermits the first and second threaded portions 84A,B of the pole 86 topass therethrough, but which is designed to engage the body 84C of thepole 86. In this manner, the shoulder portion 104 and abutting body 84Cof the pole 86 aid a user in aligning or positioning the pole relativeto the opening O.

The second threaded portion 84A of the pole 86 is configured to engagethe threaded portion 106 of the mount 102. The second threaded portion84A of the pole 86 is positioned between the first threaded portion 84Aand the body 84C. The threaded portion of the mount 102 is sufficientlylarge to permit the first threaded portion 84A of the pole 86 to passthere through, into engagement with the connector 100 of the latch 70.

As described in more detail below, in this arrangement the pole 86 actsas a tool for controlling the latch 70 and also for controlling thefilter housing 40, via a single connection. In particular, when the userextends the pole 86 into the opening O, the first threaded portion 84Bextends into the connector 100 of the latch 70 while at the same timethe second threaded portion 84A engages the filter housing mount 102.When the user turns or twists the pole 86, the pole is threaded intoengagement with the connector 100 and the mount 102. Preferably, thefirst threaded portion 84A is longer than the first threaded portion 84Bso that eventually the pole 86 bottoms out or fully engages theconnector 100 of the latch 70, thus causing the latch to turn to itsunlatched position (a tip 108 of the pole 86 may be rounded and may beconstructed of plastic or a similar durable, but relatively low hardnessmaterial so that when the end of the pole 86 hits the bottom of theconnector 100 (which may be constructed from metal), it does not damageit).

In one embodiment, the pole 86 may be weighted, such as by beingattached to a base. In this manner, when the filter housing 40 is movedto its lowered position, the weight of the pole 86 and/or base, serve tomaintain the filter housing 40 in its lowered position against thebiasing force which is applied by the extended cables 60. As oneexample, the pole 86 might comprise a solid body or the like withsufficient mass for this function. In another example, the pole 86 mightinclude a foot plate which has sufficient mass for this function orwhich a user can step on to hold it in place.

In a preferred embodiment, the pole 86 may be connected to a cart ordolly 94 for movement with the dolly 94. As illustrated in FIG. 2, thedolly 94 may have an upwardly extending handle portion 96 for grippingby a user and a base portion 98 for supporting the pole 86. The dolly 94may be wheeled for easy movement/positioning, such as by including twoor more (such as four) wheels. One or more brakes may be provided forselectively maintaining the dolly 94 in a fixed position (such as bylocking the position of one or more of the wheels). The pole 86 or othertool might be disconnectable from the dolly 94 and/or pivotally mountedto the dolly 94, such as to permit the position of the pole 86 to beadjusted relative to the dolly 94.

The air intake 20, including the filter housing 40, may be installed asan assembly, such as during the construction of a dwelling or otherstructure. An opening may be formed in a ceiling C and the air return 22and an associated filter housing 40 may be located at that opening.However, an existing air intake which utilizes a swinging grate or otherconfiguration of the prior art may also be modified to incorporate thefilter housing 40 of the present invention.

In this regard, one aspect of the invention is an air intake 20 retrofitkit. FIG. 8A illustrates one embodiment of such a kit. The kit maycomprise, for example, an assembly which comprises a mounting bracket orbody 110 to which is attached the movable supports and the filterhousing 40. The kit may also include a control tool (such as the pole 86or the combined pole 86 and dolly 94).

A user may remove the existing filter grate, such as including theassociated hinges, thus leaving the air inlet 26 of the existing airreturn 22 open. The user may then connect the filter housing 40 of thepresent invention to the existing air return 22. As illustrated in FIG.8A, the user may press the kit upwardly into the air return 22 so that asleeve portion 112 of the bracket 110 is located in the air return 22and so that one or more flange portions 114 of the bracket 110 arelocated against the ceiling C. In a preferred embodiment, the aperturesfor the latch arms 78,80 are defined by the bracket 110, so that theuser can maintain secure the filter housing 40 to the bracket 110 in itsclosed/retraced position during the mounting process (and so that theuser does not need to form apertures in the existing air return 22 orassociated support structure).

The user may then attach the bracket 110 to the structure/ceiling C withone or more fasteners F. In one embodiment, one or more openings orapertures 115 are defined through the filter housing 40 (such as theflange portion 56 thereof) through which a user may pass the fasteners Finto engagement with the one or more flange portions 114. The fastenersF are preferably used to engage or connect the flange portions 114 withthe structure, such as by connection to studs or other supports 30located in the ceiling C. For example, the fasteners F may comprisethreaded fasteners such as lag bolts or screws which may be tightenedinto studs or other supports in the ceiling C.

As illustrated in FIG. 8A, one or more gaskets or seals 116 may belocated between the filter housing 40 and the flange portions 114. Thegaskets or seals 116 might be connected to either or both of thesemembers and preferably serve to seal the space between the filterhousing 40 and the flange portion(s) 114 when the filter housing 40 isin its retracted or raised position.

Where the kit includes a dolly 94 and associated pole 86, the dolly andpole may be used by the user to stabilize and/or support the kit duringthe installation process, similar to that described below relative tothe installation shown in FIG. 8B.

Of course, in other embodiments, an air intake 20 might be modified orretrofit in other manners. For example, instead of providing a unifiedkit, a user might form apertures 86 in the sides of the air return 22(for the latch arms 78,80) and connect the mounts 62 to the air return22, such as with screws or other fasteners, whereby the filter housing40 is mounted to the air return 22 or associated support structure,rather than to a bracket or mount which is in turn mounted to the airreturn 22 or associated support structure.

A kit might also be used in a new installation, e.g. one where there isnot an existing air intake return. Such a situation might occur, forexample, during the construction of a new home wherein a ceiling C hasone or more openings therein at which an air intake is to be located.

Once again, a kit may be provide which, in one embodiment, may comprisean assembly of the mounting bracket or body 110 to which is attached themovable filter housing 40. In this configuration, the body 110 comprisesa supporting element or structure for other components of the assembly,such as the movable filter housing 40. Further, the body 110 may act asan air intake, such as by defining an air inlet and air outlet. Thefilter housing 40 is preferably movably mounted to the body 110, such asin the manner described above.

Once again, the user may raise the assembly upwardly into the ceiling Cand then mount the assembly to the ceiling, such as by using fasteners Fin the manner described above. As illustrated in FIG. 8B, and advantageof the invention is that an installer may mount or connect a controltool (such as the pole 86 which is described above) to the assembly,such as by connecting the control tool to the control tool mount whichis configured to facilitate unlatching and/or raising and lowering ofthe air filter housing. The user may use the control tool to raise theassembly upwardly, such as by extending an extendable portion thereof.The control tool or other device may thus be used to support andstabilize the assembly during the raising and mounting process. Further,in a preferred embodiment, the tool which is used to raise and supportthe assembly for mounting may be the same one which is used to unlatchand/or raise and lower the air filter housing (although the tools couldbe different).

As indicated, the body 110 preferably defines an air outlet. That outletmay be connected to an air duct or other air transporting or handlingelements. For example, as illustrated in FIG. 8B, an air duct 22 ispreferably connected to the assembly, such as the sleeve portion 112 ofthe body 110. The air duct 22 might comprise, for example, an adapter130 and a flexible hose 132. The adapter 130 might be configured tomount to the body 110 and transition the size of the opening in the body110 to the flexible hose 132. Of course, other types of ductwork orelements might be mounted or connected to the assembly and their meansof connection might vary (fasteners, threading, tightenable bands, slipfit, etc.).

Once the assembly is mounted, the user may raise and lower the filterhousing 40 and associated filter 46 relative to the body 110 and theceiling C, in the manner described above. When the tool which is used tomount the assembly is the same as the control tool which is designed tounlatch and raise/lower the filter housing, the user may use that toolafter installation in order to move the filter housing to change thefilter, etc.

In accordance with this aspect of the invention, an air intake may beconfigured using an assembly of the invention by simply mounting anentire assembly having a movable filter housing 40 (rather than viaretrofitting an existing air duct). The assembly is easy to installusing the control tool and, when complete, includes the filter raisingand lowering feature of the present invention.

Additional details of the invention will be appreciated from adescription of a method of replacing a filter in accordance with theinvention.

As illustrated in FIG. 6, a user of an HVAC system may wish to check orreplace an air filter 46 which is associated with an air intake 20having the filter housing 40 of the present invention. In its useposition, the filter housing 40 of the invention is located in the airinlet 26 of the air return 22, and is thus in a first or raised positionat the ceiling.

The user must thus first lower the filter housing 40. In one embodiment,this requires that the user first unlatch or unlock the filter housing40 so that it can be moved. As indicated above, this may require theuser to unlock a latch 70. Once unlocked, the user must pull the filterhousing 40 downward.

In a preferred embodiment, this is accomplished by use of the controltool. As described above, this may comprise a pole 86. The user mayattach the pole 86 to the filter housing 40 and latch 70. As illustratedin FIG. 6, a user may move the pole 86 into position, such as by movingthe dolly 94 under the filter housing.

The user may then extend the pole 86 upwardly until it engages thefilter housing 40 and latch 70 (where the pole 86 is mounted to thedolly 94 and has a bottom section 90 and a top section 88, the user mayextend the top section 88 towards the filter housing 40). In oneembodiment, the user rotates the pole 86 (or at least the top section88) so that the first threaded portion 84B engages the latch connector100 and the second threaded portion 84A engages the mount 102. Continuedturning of the pole 86 eventually causes the first threaded portion 84Bto so engage the connector 100 that the pivot 72 is rotated, thusunlatching the arms 78,80.

Once unlocked or unlatched, the user may pull downwardly on the filterhousing 40 via engagement of the pole 86 with the filter housing 40. Asthe user pulls downwardly, the cables 60 unwind or are otherwiseextended, as illustrated in FIG. 7. Once the filter housing 40 has areached a position where the user can reach the filter 46, the user maylock or maintain the position of the filter housing 40. In oneembodiment, where the pole 86 has a top section 88 which can be movedrelative to a bottom section 90, the user may lock the position of theupper section. At that point, the weight of the pole 86 and/or dolly 94preferably maintains the filter housing 40 in the desired position. Inone embodiment, the filter housing 40 may be lowered between 3 and 8feet, though the distance or range of distances may vary depending uponthe installation (including floor to ceiling height of the structure).In one embodiment, the filter housing 40 can be lowered to around 3 to 6feet above a floor or other support surface which is located below theair intake 20.

The user may then slide the existing air filter 46 out of its filtermount 48 at the top of the filter housing 40. The user may then eitherclean that filter and re-insert it, or insert a replacement air filter46 into the mount 48. Most importantly, during this process the filterhousing 40 is maintained in a lowered, stable position (the filterhousing 40 will not swing around and potentially hit the user, a wall orthe like, because it is secured by the control tool (such as the pole 86and/or dolly 94).

The user may then raise the filter housing 40 back to its first,retracted position. In a preferred embodiment, the user preferablyallows the upper section of the pole 86 to move relative to the bottomsection 90. The filter housing 40 preferably moves upwardly as a resultof the biasing of the cables 60.

In a preferred embodiment, use of four cables 60 balances the filterhousing 40 so that it moves smoothly upwardly into the air inlet 26 (anddoes not tilt or become offset and thus not seat within the air inlet26). Once the filter housing 40 is raised, the user preferably againlocks or latches it, such as by rotating the pole 86. As indicatedabove, in one embodiment, when the user twists the pole to release itfrom the pivot 72, it automatically turns the pivot 72 to latch thelatch 70 (by causing the free ends of the arms 78,80 to enter theirmating apertures 86). With the filter housing 40 latched into its raisedposition, the user may move the pole 86 and dolly 94 away.

Once the filter housing 40 is raised, it is positioned at the air inlet26. Air which is drawn by the air handling system thus flows from thearea at the exterior or bottom 44 of the filter housing 40 through theopenings 54, through the one or more air filters 46, into the air return22. The one or more air filters 46 are maintained in position (and arenot drawn upwardly into the air return 22) because they are secured bythe filter mount 48.

It will be appreciated that the invention may have a variety of otherconfigurations than exactly as described above. First, the filterhousing 40 may be configured to support more than one air filter. Forexample, if the air inlet 26 is approximately 40 inches by 40 inches,the filter housing 40 may be configured to support two 20 inch by 20inch filters (either by one or more than one air filter mount 48). Asanother example, the filter housing 40 might be configured to supporttwo or more filters in a stacked relationship. For example, asillustrated in FIG. 11, the filter housing 40 may define one or moreslots or other supports for supporting multiple filters in a stackedrelationship. In the embodiment which is illustrated, the filter housing40 will support up to three filters 46A, 46B, 46C (though a user mightuse as few as one or two). Of course, the filter housing 40 mightsupport additional or other numbers of filters. In this embodiment, thefilters are supported to that there is a gap between them. However, theycould be supported in a manner where they contact or rest upon oneanother. It will be noted that the filters might comprise anycombination of a HEPA filter, a carbon or charcoal filter, a pre-filter,a standard filter, a poly-coated glass filter, etc., depending upon thedesired application. For example, the bottom filter 46C might comprise apre-filter, a middle filter 46B might comprise a standard filter or anodor trapping filter, while the top filter 46A might comprise a HEPAfilter. While the bottom filter 46C might rest directly upon the filterhousing grate or grill, as illustrated in FIG. 11, the bottom filtermight be supported above the grill, thus facilitating less turbulent(and thus quieter) air flow and facilitating the use of an air pressuredifferential tube as detailed herein, for among other reasons.

Other filter retaining mechanisms may be used other than the mount 48 asdescribed above. Preferably, however, the filter retaining mechanismsecures the one or more air filters to the filter housing 40 so that theone or more filters move with the filter housing 40 when the filterhousing is raised and lowered, and so that the position of the one ormore air filters is maintained (such as to prevent, for example, thefilter(s) from moving askew and blocking the filter housing 40 frombeing moved into its retracted position and ensuring that the filter(s)is properly located between the opening(s) 54 in the filter intake 40and the air inlet 26). For example, clips or other types of mounts mightbe utilized to accomplish this task.

As indicated, in one embodiment, the filter housing 40 can selectivelybe locked or latched into its retracted position. Other mechanisms thanthe latch 70 described above might be utilized. For example, a latchwith 1 arm or more than 2 arms (such as 4 arms extending 90 degrees toone another) might be used. Locks or latches which rotate, slide orotherwise move between locked and unlocked positions may be utilized.For example, a latch might be located along one or more sides of thefilter housing 40. Such latches might be moved with various controltools. A particular advantage of the latch 70 of the present inventionis that it is centrally controlled and thus may be actuated by the samecontrol tool which a user utilizes to lower the filter housing 40 (it ispossible for the invention to have a configuration in which one controltool is used to control the latch(es) 70 and another is used to controlthe position of the filter housing 40).

Various means may be used by a user to move the filter housing 40 fromits retracted to its lowered position and thus the tool connector of thefilter housing 40 and/or the control tool, may vary. As described above,in a preferred embodiment, the control tool comprises a mechanicallyactuated tool in the form of a pole having a threaded end. However,other tools or devices might be utilized, and such tools or devicesmight connect to the filter housing 40 in various manners. For example,the filter housing 40 might include a downwardly extending hook. A usermight attach a weighted rod to the hook in order to pull the filterhousing 40 downwardly and maintain it in its lowered position. Thefilter housing 40 might define a socket or other types of mounts forselectively accepting or mounting a control tool thereto.

While a cart or dolly 94 may be used to position the pole 86 and alsomaintain the pole 86 in a fixed position, other devices could beutilized. For example, the bottom of the pole 86 might be formed with orbe connected to a simple weighted base. Also, in other configurations,the mounts 58 might have a lock-out position or the like, wherein at oneor more positions the biasing mechanisms do not bias the cables 60upwardly (such as catches which engage the pulleys at designed positionsor the like, but which catches can be released when the user is ready toraise the filter housing 40 back to its raised position).

FIGS. 9 and 10 illustrate another embodiment of the invention. In thisconfiguration, the means for movably connecting again comprise one ormore cables 60 which are biased by one or more mounts, such as biasedpulleys 66 (as illustrated, the pulleys 66 may be mounted in a channelportion of the air filter, such as to keep the pulleys out of the airflow path). In this configuration, however, the pulleys 66 are mountedto the air filter housing 40, with a first end of each cable 60connected to or movable by the pulley, and a second end connected to theair return 24. Preferably, the pulleys 66 are configured to wind thecables 60, thus biasing the air filter housing 40 to its raisedposition. FIGS. 9 and 10 illustrate a configuration in which pairs ofpulleys 66 and associated cables 60 are located at opposing sides of thefilter housing 40 (although only one side of the filter housing 40 isillustrated in FIGS. 9 and 10). However, there could be a lesser orgreater number of pulleys 66 and cables 60 and/or their position mightvary (for example, there might be a single pulley 66 and associatedcable 60 at two opposing sides of the filter housing 40). It will beappreciated that, while not shown, the pulleys 66 could be mounted inone or more housings or mounts (such as mounts 62 as described above).

In this configuration, the means for moving preferably includes one ormore stops or a stop mechanism which are configured to prevent thepulleys 66 from winding the cables 60. As illustrated in FIGS. 9 and 10,the stop may comprise one or more brakes 120. The brake 120 ispreferably configured to selectively prevent movement of one or all ofthe pulleys 66. In an embodiment such as is illustrated in FIGS. 9 and10 where two pulleys 66 are mounted adjacent to one another, the brake120 may comprise a pin 122 or similar member which can be moved betweena first position in which it does not engage the pulleys 66, thuspermitting them to rotate, and a second position in which it engages thepulleys 66, preventing them from rotating.

Preferably, the stop includes one or more controls for selectivelyengaging the stop, such as the brake 120. In one embodiment, the controlmay include a cable 124 which can be actuated by a user.

In one configuration, the cable 124 may extend from the brake 120 to thepivot 72 (see FIG. 4). The pin 122 of the brake 120 may be biasedupwardly into the braking position, such as by one or more springs orother biasing mechanisms. The cable 124 may be connected to the pivot 72so that then the user actuates the pivot 72 to unlock the latch 70, theuser can also control the brake 120 by pulling the pin 122 downwardlyinto a release position. For example, the cable 124 may be connected tothe pivot 72 so that when the user rotates the pivot 72 with a tool,such as the pole 86, the user also disengages the brake. This permitsthe user to unlock the latch 70 to release the air filter housing 40,and also release the brake 120 so that the user can pull the air filterhousing 40 downwardly.

When the user has pulled the air filter housing 40 down to the desiredposition, the user can release the pole 86. At that time the brake 120preferably automatically sets (such as by biasing the pin 122 upwardly).This causes the position of the air filter housing 40 to be fixed by thebrake 120. The user may then replace, clean, or inspect the air filter,etc., while the air filter housing 40 is securely maintained in itslowered position.

When the user is done, the user can turn the pole 86, thus causing thecontrol 124 to release the brake 120. At that time, the pulleys 66 windthe cables 60, thus causing the air filter housing 40 to move upwardlyto its retracted position. The user may then release the pole 86, atwhich time the latch 70 again automatically moves to its locked positionand the brake 120 automatically re-engages.

It is noted that in this configuration, the pole 86 or other tool neednot be weighted because the weight of the pole 86 is not required tomaintain the filter housing 40 in its lowered position.

As indicated, there may be more than one brake 120. For example, a brake120 might be provided for each pulley 66. Also, the configuration of thebrake 120 might vary from that described above. For example, each pulley66 might comprise or include teeth which may be selectively engaged by alever. The lever may be movable between a position in which it engagesone of the teeth (locking or braking the pulley 66) and a position inwhich it does not engage the pulley (allowing the pulley 66 to rotate).In general, the one or more brakes preferably comprise one or moreelements which allow a user to selectively prevent the means for movingfrom biasing or moving the filter housing 40 upwardly, thus allowing theuser to selectively maintain the filter housing 40 in one or moredesired lowered positions.

As indicated, the user can preferably control the one or more brakes viaone or more controls. Preferably, the one or more brake controls arelocated at the filter housing 40. For example, it is possible for theone or more brakes 120 to be located at the air return 24, but have thebrake control associated with the filter housing 40 (whereby when thefilter housing 40 is lowered, the brake control at the filter housing 40remotely controls the one or more brakes which are located up at the airreturn 24).

In one embodiment, the control can be actuated by the same tool which isused to control the latch 70 and/or raise and lower the filter housing40. As indicated, in one embodiment the control is controlled byrotation of the pole 86 which also affect locking or unlocking of thelatch 70. However, the brake control could be actuated or controlled inother manners. For example, the brake control might be actuated by a tipof the pole 86 pressing upwardly, while locking and unlocking of thelatch might be accomplished by rotating the pole. Of course, it is alsopossible for the one or more brakes 120 to be controlled with othertools or controls than those which are used to lock and unlock the latch70 and raise and lower the filter housing 40. While the brake 120 andthe associated control may be mechanical, in other embodiments theymight be electro-mechanical in configuration. For example, the controlmight comprise a button which the user pushes which causes an electricalsignal to be sent to a solenoid which selectively engages or disengagesthe brake.

In one embodiment of the invention, one or more indicators may beprovided regarding a condition of the filter housing 40. For example, avisual indicator may be provided which indicates whether the latch 70 islocked or unlocked. As one example, when the latch 70 is located, a redindicator may be provided to the user and when the latch 70 is unlocked,a green indicator may be provided to the user. The indicators mightcomprise, for example, red and green dots which selectively align with awindow in the filter housing 40, depending upon a position of the pivot72. Likewise, a similar indicator might be provided to the userregarding a condition of the one or more brakes 120.

It is also possible for filter housing 40 to be raised and/or lowered byother types of tools other than the pole 86 described above. Forexample, each pulley 62 might be drivable by a tool, such as viarotation of a pole or a shaft of a power driven drill. The user mightengage the tool with a socket and rotate the tool (pole, drill shaft) tocause the pulleys to wind or unwind (depending upon the direction ofrotation). In this and other configurations, the mounts 58 may not berequired to include a biasing mechanism for biasing the filter housing40 upwardly, or the biasing force which is required may be lessened).

In another embodiment, the filter housing 40 might be raised and/orlowered by one or more motors. The one or more motors might be used todrive the pulleys 62. In the embodiment described above, the filterhousing 40 must be pulled downwardly against the pulley bias which isnecessary to raise the filter housing 40. In this embodiment, onceunlocked, the pulleys 62 might freewheel, thus allowing the filterhousing 40 to simply lower with the aid of gravity. Then the one or moremotors may be utilized to rotate the pulleys 62 to raise the filterhousing 40 upwardly.

In one embodiment, the one or more motors might by controlled by aremote control or via a switch which is provided near the filter housing40, such as below the filter housing 40 on a wall of a home, building,etc., where the filter housing 40 installed.

In one embodiment, the filter housing 40 may be configured to be engagedand unlatched using a pole 86 or other tool having a single engagingfeature. For example, referring to FIG. 5, the pole 86 might have asingle threaded tip portion. The threaded portion 106 of the opening Oand the tool mount 100 of the pivot 72 might be of the same size,whereby the threaded tip of the pole 86 is threaded upwardly into bothopenings. In yet another embodiment, the opening O might be enlarged soas to permit the pole to be extended there though. Once the pole 86 isengaged with the pivot 72, the pole 86 can be used to both unlatch thelatch 70 (by turning the pole 86), to move the filter housing 40 (bypulling down on the pole 86, since the pole is engaged with the pivot72, which is in turn mounted to the filter housing 40), and to controlthe one or more brakes 120.

One problem with existing air returns 22 is that they are box-shaped andhave abrupt corners, such as walls and a top portion which meet at 90degree angles. As one aspect of the invention, a user might install anair return 22 having smooth transitions between the surfaces thereof,such as illustrated in FIG. 2. This air return 22 might be installed aspart of a new installation (instead of an existing square box return) orit might be inserted into an existing box-shaped air return. Forexample, the bracket 110 might have a top air return or sleeve portion112 which fits into and supersedes the existing air return 22 (forexample, referring to FIG. 8, a top portion of the bracket 110 mighttaper to a duct or tube which is configured to extend all the way intoan existing outlet of the existing air return 22). In this manner,additional benefits (a quieter system) may be realized in addition tothe filter access benefits described herein. In one embodiment, thebracket 110, the adapter 130 and/or the return 24 might be vacuum formed(such as from plastic or another polymer) to have a smooth surfaces andsmooth radius transitions between sections at different angles, thusfacilitating less turbulent (and quieter) air flow).

In one embodiment, the filter system of the invention may include afilter status indicator. This feature has particular applicability tothe filter housing 40 of the present invention, but might be used withother filter supports or housings, including those of a more traditionalstyle.

FIG. 13 illustrates a filter housing 40 which is similar to thatillustrated in FIG. 8A and described above. In this embodiment, thefilter housing 40 defines or includes at least one air flow passage orpitot tube 200. The air pitot tube 200 has an inlet 202 and an outlet204. In this embodiment, the inlet 202 is preferably positioned at theintake or exterior side of the filter housing 40 (e.g. coupled to the“ambient” air), such as before the air passes through the first (oronly) filter 46. The outlet 204 is preferably positioned at thedownstream side of the filter housing 40, such as after the air passesthrough the last (or only) filter 46 (e.g. at the interior side alongthe path to the blower). The air pitot tube 200 preferably comprises atube, passage or the like through which air may freely flow.

The air pitot tube 200 may be configured in various fashions. Asillustrated, the inlet 202 aligns with or extends through an opening inthe filter support flange 50 a (see also FIGS. 3 and 11). The outlet 204aligns with or extends through an opening in the air return or sleeveportion 112 of the filter housing 40. As illustrated, the air pitot tube200 runs along the outside of the bracket 110, such as between thefilter housing 40 and the associated support structure (such as theceiling C, etc.). Of course, the air pitot tube 200 might be formed aspart of one or more components of the filter housing 40, such as wherethe air pitot tube 200 comprises a passage through one or more of thosecomponents.

The air pitot tube 200 is configured to provide an indication of thestatus of the one or more air filters 46. In particular, when the airfilters are clean, air will flow through the filters 46 at a high rate.The air flow rate through the air pitot tube 200 will then be low (andthe differential pressure between the inlet and outlet ends of the tube200 will be low). However, as the filters get clogged, the air will flowthrough the filters 46 at a lower rate. The air flow rate through theair pitot tube 200 will then rise, as will the differential pressurethrough the tube 200.

In one embodiment, means are provided for indicating a status of the airfilters, preferably based upon the air flow through the pitot tube 200.In one embodiment, this comprises at least one visual indicator 206 anda means for controlling the visual indicator. In one embodiment, themechanism may be very simple: the visual indicator 206 may comprise oneor more lights, such as two or more lights. Based upon the airflow/pressure in the pitot tube 200, a circuit contact may close acircuit between a power source (such as one or more batteries) andeither the first light or the second light, etc. For example, asillustrated in FIG. 14, a battery 208 might be mounted on a movingplunger 210 which is mounted in a housing 212. An interior space of thehousing 212 is linked to the pitot tube 200. The position of the plunger210 may change based upon the air flow/pressure in the pitot tube 200(as illustrated, the plunger 210 may be biased to a first position, suchas a “clean filter” position, such as by one or more springs 214, andwherein the plunger moves rearwardly as the air flow and pressure in thepitot tube 200 increase), wherein in a first plunger position thebattery may be part of a closed circuit that lights a first light 206,but when the plunger moves to a second position the battery may then bepart of a closed circuit that lights a second light 206B (and theremight be a third light 206C, fourth light, etc.). In this manner,changes in air flow/pressure in the pitot tube 200 cause one moremembers to move, wherein the position of the one or more membersdetermines which visual indicator is illuminated.

In one embodiment, the visual indicator 206 might comprise, for example,a first green light, a second yellow light and a third red light, or anLED which is capable of generating light of those colors. In thisembodiment, the first green light might be illuminated when the airflow/pressure associated with the air pitot tube 200 is low (air filtersare clean), a second yellow light might be illuminated when the airflow/pressure associated with the air pitot tube 200 is medium (airfilters are between clean and dirty) and a third red light might beilluminated when the air flow/pressure associated with the air pitottube 200 is high (air filters are dirty).

Of course, other configurations are possible. For example, in oneembodiment the filter status indicator might include a controller. Thecontroller might receive input from an air sensor (such as an airpressure or air flow sensor) or other element (such as based upon theposition of a moving plunger). The controller might then be configuredto control the activation of one or more lights, such as theabove-referenced green, yellow and red lights, or to control the coloroutput of a single multi-color LED. Further, the air passage(s) andsensors could have other configurations, such as where differentialpressure is determined by measuring total pressure on the interior sideand static pressure on the exterior side of the air filter(s) and thendetermining the differential therefrom, in which case one air passagemight lead to the sensor from the exterior side and another from theinterior side.

Of course, in the configuration in which the filter indicator includesone or more lights, the filter indicator has or is powered by one ormore power sources. The power source might comprise one or morebatteries, coupling to an external power supply, etc.

Preferably, the filter indicator is visible to the user of the filterhousing 40 when the filter housing 40 is in its raised position. Forexample, as illustrated in FIG. 13, the visual indicator 206 might bevisible through an opening in the filter housing grate, such as theflange 56 thereof. In another embodiment, the visual indicator 206 isaligned with the control tool opening O (see FIG. 5), whereby when thecontrol tool is not located in the opening, the user can look up and seethe condition of the filter(s) by viewing the visual indicator throughthe opening O.

In one embodiment, the filter indicator may be associated with thefilter housing 40 in a manner which allows it to be raised and loweredtherewith. For example, the air passages may comprise tubes which aresupported by the filter housing rather than being passages located inthe surrounding support structure or ceiling. As one example, one ormore tubes which define the air passage(s) of the filter indicator mightbe mounted to or be formed as a portion of the filter mount 50. One ormore tubes or passages may have an opening in the grate or otherlocation below the filter(s) 46, and one or more tubes or passages mayhave an opening above the filters 46. In the case of a battery poweredindicator, this allows the filter indicator to be lowered downwardlywith the filter housing to that the user can easily access and replacethe batteries. Further, in this configuration, the filter housing 40with the filter indicator comprises a single unit which can simply bemounted or installed as noted above without having to modify thesurrounding support structure or ceiling to include the filter indicatorfeatures.

The invention has a plurality of distinct advantages over the prior art.First, in accordance with the invention, the position of an air filtercan be changed from a raised, use position to a lowered, accessposition. Movement of the air filter can be accomplished by simplyconnecting a tool to an associated filter housing and lowering thefilter housing.

This feature eliminates the need for the user to use a ladder to accessthe air filter housing and the enclosed filter in the case of existingHVAC systems with air intakes which are located in the ceiling. Thus, auser does not risk falling off of a ladder and injuring themselves.

Another advantage of the system is that once the filter housing islowered, the control tool (such as the pole and dolly) can be used torestrain the filter housing during filter replacement or the one or morebrakes may be used to restrain the filter housing. This frees the userto use both of their hands to remove and replace the air filter (becausethe user does not need to hold onto the filter housing to maintain it inits lowered position or to fix the position of the filter housing tokeep it from swaying).

One advantage to the control arrangement of the invention, including thecontrol tool, is that in order for the tool to unlatch the latch 70 andone or more brakes 120, it must be fully engaged with the filter housing40. Thus, if the latch 70 is successfully unlatched and the one or morebrakes 120 are successfully disengaged, a user is assured that the toolis engaged and that they can then pull downwardly on the filter housing40 to lower it (thus eliminating the risk that the user does notsufficiently connect the tool and upon pulling the filter housing 40down, the tool comes loose (although in the preferred embodiment, insuch a configuration the one or more brakes 120 are also then notdisengaged and the filter housing 40 is also prevented from abruptlyraising back up).

Another advantage of the system is that when the filter housing israised, it can be securely locked or latched. This ensures that themovable filter housing is retained during operation of the HVAC system.Most preferably, however, the locking or latching system can be actuatedby a user from the ground (i.e. without climbing a ladder).

Yet another advantage of the invention is that the components of thefilter housing 40, including the movable supports 58, are not located inthe air flow path through the air intake 20. Thus, air flow is notimpeded or interfered with and those components are less likely tobecome fouled with dirt. This contrasts with some existing systems wheremotors, balancers or the like are located inside of the air return 22directly in the air flow path, thus impeding air flow, causing thecomponents to become dirty, and introducing noise and vibration as aresult of the movement of air over the components.

Another advantage of the invention is that an existing air intake with aswinging or hinged grate of the prior art can easily be modified toprovide the filter access features of the present invention. Asdescribed above, one benefit to the invention is its simplistic design,thus permitting a movable filter housing to be connected to an existingair intake.

It will be understood that the above described arrangements of apparatusand the method there from are merely illustrative of applications of theprinciples of this invention and many other embodiments andmodifications may be made without departing from the spirit and scope ofthe invention as defined in the claims.

What is claimed is:
 1. A raisable and lowerable filter housing for anair heating/cooling system having an air intake located in a ceiling,the air intake comprising an air return having an air inlet, comprising:an air filter housing, said housing comprising an air intake gratehaving an outer side and an inner side, a plurality of filter mountslocated at said inner side and spaced from said inner side of said grateand from one another for supporting at least two air filters in aspaced, stacked relationship above said inner side of said grate andarranged for movement with said air filter housing; at least a first anda second extendable connector, each of said extendable connectors havingat least a first portion connected to said air filter housing and asecond portion for connection to said ceiling; wherein said air filterhousing is movable between a raised position in which said grate ispositioned at said air inlet of said air intake return and said at leasttwo air filters associated with said air filter housing are configuredto filter air passing through said air intake grate into said air intakereturn of said air heating/cooling system, and a lowered position inwhich said entire air filter housing and said two or more air filtersassociated therewith are positioned a distance vertically below said airintake, permitting a user to remove one or more of said at least two airfilters from said air filter housing for replacement; and a biasingmechanism associated with each extendable connector, each biasingmechanism configured to bias its associated extendable connector to aretracted position corresponding to said raised position of said airfilter housing, each biasing mechanism including a bias adjustmentmechanism, whereby a user may independently adjust a biasing forcegenerated by each biasing mechanism.
 2. The raisable and lowerablefilter housing in accordance with claim 1 wherein each extendableconnector comprises a cable.
 3. The raisable and lowerable filterhousing in accordance with claim 2 wherein said biasing mechanismcomprises a coil spring.
 4. The raisable and lowerable filter housing inaccordance with claim 3 wherein a second portion of each biasingconnector is mounted to a pulley which is supported by said ceiling andwherein a coil spring is associated with each pulley.
 5. The raisableand lowerable filter housing in accordance with claim 1 wherein eachfilter mount defines a generally horizontal filter accepting slot. 6.The raisable and lowerable filter housing in accordance with claim 1further comprising at least one air filter condition indicator.
 7. Theraisable and lowerable filter housing in accordance with claim 6 whereinsaid air filter housing has an exterior side and an interior side whensaid air filter housing is in said raised position and said indicatorcomprises an air passage extending from said exterior side to saidinterior side, at least one air pressure sensor associated with said airpassage and at least one indicator which provides an output based uponsaid output of said air pressure sensor.
 8. The raisable and lowerablefilter housing in accordance with claim 7 wherein said air passagecomprises a pitot tube and said at least one indicator comprises atleast one light.
 9. The raisable and lowerable filter housing inaccordance with claim 8 wherein a color of said at least one lightchanges depending upon said output of said air pressure.
 10. The movablefilter housing in accordance with claim 1 further comprising at leastone latch configured to be moved between a locked position in which saidlatch engages said air filter housing and said support structure whensaid air filter housing is in said raised position, thus preventingmovement of said air filter housing, and an unlocked position whichpermits said air filter housing to be moved between its raised and itslowered position.
 11. The movable filter housing in accordance withclaim 10 wherein said latch comprises a pivot which is mounted to saidair filter housing and at least one arm which is connected to saidpivot, wherein movement of said pivot causes said at least one arm tomove between a retracted position in which said at least one arm doesnot engage said support structure when said latch in said unlockedposition and an extended position in which said at least one arm doesengage said support structure when said latch is in said lockedposition.
 12. The movable filter housing in accordance with claim 11wherein said pivot is aligned with said threaded opening for a controltool.
 13. The movable filter housing in accordance with claim 12 saidcontrol tool is configured to actuate both said pivot and engage saidthreaded opening.
 14. The movable filter housing in accordance withclaim 1 wherein said air inlet of said air intake is generallyhorizontally extending.
 15. The movable filter housing in accordancewith claim 1 wherein said air filter housing is configured to be movedbetween said raised and lowered positions in a generally horizontalorientation.